Many systems such as Global Positioning System (GPS) rely on the entry of multiple coordinates using keypads. In a GPS system, if one digit is mistyped then the navigation system might contain a positional error in the order of hundreds of kilometers. Equally, a navigational error in the order of meters can be dangerous and difficult to spot detect. Navigational errors are more likely in adverse climatic or acoustic conditions and many other situations where accuracy is often critical.
U.S. Pat. No. 3,593,311 discloses a data recorder with single operator entry-verify control, in which each character entered is compared with the character it is replacing and an error control bit is produced for an unequal comparison, requiring verification of any data entered during a verify cycle.
U.S. Pat. No. 6,748,568 discloses an apparatus and method for verifying proper data entry and detecting common typing errors, in which common keyboard typing errors are detected by using at least one parity bit. When error is detected, the data input operator can be warned or entry may be automatically suspended.
These approaches have the disadvantage that although errors in operator data entry may be detected, the result of such detection is only to require operator verification of the entry or to automatically suspend entry. A need therefore exists for a system and method for data entry wherein the abovementioned disadvantage is alleviated.